Internal-combustion engine.



No. 644,798. Patented Mar. 6, won.

I A. J. FRITH.

INTERNAL COMBUSTION ENGINE.

(Application filed Oct. 23, 1899.)

(No Model.)

25 1/ .2 ZZZ/9. 4. 1 1 .2 (72 TB, DZ 75 ll l I i- E I WITNESSES 2 v jINVENTOR mil 4 ATTORN EYS rTED STATES PATENT Price.

ARTHUR J. FRI'II-I, OF NEW YORK, N. Y., ASSIGNOR TO THE DIESEL MOTORCOMPANY OF AMERICA, OF NEW YORK.

lNTERNAL -COMBUSTION ENGINE.

SPECIFICATION forming part of Letters Patent No..644,798, dated March 6,1966. Application filed October 28, 1899; Serial No. 734,479. (Nomodel.)

To aZZ whom, it may concern.-

Be it known that I, ARTHUR J. FRITH, a citizen of the United States, anda resident of the city of New York, county of New York, and State of NewYork, have invented certain new and useful Improvements inInternal-Oombustiou Engines, of which the following is a specification.

My invention relates to improvements in internal-combustion motors ofthe Diesel type. These engines work on a four-stroke cycle as follows:The combustion of fuel injected f romthc fuel-valve gives a pressure onthe inward stroke of the piston. On the next outward stroke the wastegases or products ofcombustion are expelled from the cylinder. On thenext inward stroke the cylinder fills with fresh air drawn in from theatmosphere. This air is compressed on the succeeding outward stroke to atemperature sufficient to ignite the fuel, which is now injected fromthe fuelvalve. Combustion of the mixture of air and fuel then ensues andthe cycle recommences. For the successful operation of these engines itis essential that the temperature attained by the air in the cylinderduring the period of compression on the fourth stroke of the cycle behigh enough to cause ignition of the fuel when injected from thefuel-valve. It is also important that on the introduction of the fueluniform and complete combustion shall take place as quickly as possible.Owing to the large amount of relatively-cooler metallic surface to whichthe air is exposed at this point and the proximity of the usualwaterjacket the loss of heat between the time of compression and that ofthe admission of the fuel may become so great as to preclude a properignition. This may be compensated for by an excessive compression, butonly at the expense of additional energy.

In the German engines it has been the practice to simply compress theair in the top of the cylinder, thus forming a cylindrical body of airexposed to the combined cooling effect of the entire cylinder end, thepiston-face, and a strip around the cylinder equal in length to thecircumference of the cylinder and in Width to the distance between thecylinderhead andthe piston=face at the outer limit of the stroke. As thestrip last mentioned is usually backed by a water-jacket it is readilyapparent that the construction gives a very large amount ofcooling-surface per cubic inch of inclosed air. Now itis evident that ifthe metallic surface to which the air is exposed can be diminished thedetrimental cooling of feet will be considerably lessened; and theobjects of my improvements are to provide a clearance-space in thecylinder of less surface area than has been hitherto employed and toadord facilities for the rapid introduction and ignition of the fuel.Otheradvantages will be apparent from the specification. I attain theseobjects by the mechanism illustrated in the accompanying drawings, inwhich- Figure 1 represents a longitudinal section through the head endof an engine-cylinder passing through the axis of the admission port,the section being taken on line 1 1 of Fig. 2, the crank end of thecylinder and ad- I j acent parts of the engine being broken away.

mission-port, D the fuel-valve, E the waterjacket, G the safety-valve, Hthe air-admission valve, and K the escape-valve, of an engine of theDiesel type. In the ordinary engine a considerable clearance is leftbetween the face of the piston and the internal face of thecylinder-head. In this engine I bring the piston-face at the outer limitof the stroke in substantial contact with the cylinder-head,

(see dotted lines in Figs. 1 and 2,) so as to give practically noclearance at that point. I provide for air-space, however, by forming inthe face of the piston a groove or channel F, preferably semiconical inshape, (see Fig. 1,) its axis in a plane passing through the axis of theadmission-port, With the larger end of the cone nearest such port. Whenthe piston is at the top of the stroke, this channel F alines withtheport 0, and the entire body of compressed air is concentrated in thistemporarily-formed chamber or tunnel. As is apparent, a much less areaof coolingsurface is exposed per unit of cubical contents of air than inthe ordinary form of clearance-space.

The fuel emerges from the fuel-valve D in a spray or jet of more or lessconical shape and is at once surrounded by compressed air of atemperature considerably above its ignition-point, its primary contactbeing with the very hottest portion of such airnamely, the centralportion. Combustion immediately occurs and is uniform throughout thecircumference of the cone. By reason of the long narrow shape of theclearance-space the particles of fuel mix more thoroughly'andintimatelywith the air than in the olderengines. The mixture of fuel andair is quickly projected across the piston,and the combustion issubstantially simultaneous not only throughout the circumference of thecone, but also throughout the length thereof.

In the former engines where the fuel was introduced through a port inthe head of the cylinder the jet struck against the face of the pistonand was deflected toward the sides of the clearance-space before itcould ignite, The objectionable feature of this method of introductionlay in the fact that the jet striking the comparatively-cold piston-facewas apt to deposit carbon thereon with. a corresponding loss of theoriginally-available energy. Myimprovement avoids this objection, for byits use the fuel has opportunity to move in a clear space entirelyacross the cylinder in the line of its entry before it can come incontact with any part of 'the metal cylinder or piston. The constructionis therefore most perfectly adapted to prevent the deposition of carbonin any part of the ignition-space.

In actual use it is found impossible to exclude entirely the air frombetween the adjacent plane surfaces of the cylinder end and piston-face.Its amount is so small, however, as to exercise practically no harmfuleffect on the tendency of the fuel to ignite, since it bears but a smallratio to the large body of highly-heated air in the channel F, and it isimmediately reheated by the great heat evolved in the initial stages ofcombustion. As a factor in results it can therefore be safely neglected.

In Figs. 3 and I are shown modifications. The channel may be locatedentirely within the cylinder-head or partly in the cylinderhead andpartly in the piston, the two channels uniting to form one channel atthe time of combustion of the charge. Fig. 3 shows an engine with achannel entirely in the cylinder-head, and Fig. 4 with the channelpartly in the cylinder-head and partly in the piston.

I do not limit myself to a channel of a conical or semiconical shape,though that form I believe to be preferable, since it corresponds morenearly to the shape of the fuel-jet. Channels of a cylindrical,senlicylindrical, polygonal, or other shape I consider within the scopeof my invention. It is desirable to make the channel and admission-portof similar cross-section so far as possible. The depth of the channelmay be varied to provide greater or less compression, as desired.

What I claim as my invention, and desire to secure by Letters Patent,is-

l. In an internal-combustion engine, the combination of a cylinder, ahead on said cylinder, a piston in said. cylinder, said piston andcylinder-head being so shaped with respect to each other as to formbetween them a channel to serve as a clearance-space andignition-chamber, the longitudinal axis of said channel lyingsubstantially at right an gles to the longitudinal axis of the cylinder,substantially as described.

2. In an internal-combustion engine, the combination of a cylinder, ahead on said cylinder, a piston in said cylinder, said piston andcylinder-head being so shaped with respect to each other as to formbetween them a channel, the longitudinal axis of said channel coincidingwith the diameter of the cylinder, and lying substantially at rightangles to the longitudinal axis of the cylinder, to serve as aclearance-space and ignition-chamber, substantially as described.

3. In an internal-combustion engine, the combination .of a cylinder,ahead on said cylinder having a plane inner face, a piston in saidcylinder, having a plane face opposed to the plane face of thecylinder-head and a channel in the piston-face, the longitudinal axis ofsaid channel coinciding with a diame-- ter of the cylinder, and lyingsubstantially at right angles to the longitudinal axis of the cylinder,to provide clearance between the piston and the cylinder-head,substantially as described.

4:. In an internal-combustion engine, the combination of a cylinder, ahead on said cylinder having a plane inner face, said cylinder providednear said. head with a lateral admission-port, a piston in saidcylinder, having a plane face opposed to the plane face of thecylinder-head and a channel in the pistonface to provide clearance, thelongitudinal axis of the channel lying substantially at right angles tothe longitudinal axis of the cylinder, and in a plane passing throughthe longitudinal axis of the cylinder and the axis of theadmission-port, whereby at the outer limit of the stroke the channel andport aline, and provide a continuous chamber for the admission of thefuel charge, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

ARTHUR .I. FRITI'I.

\Vitnesses:

G. A. TAYLOR, THEODORE I. DORMAN.

